Highlights: "We demonstrate that inhibition of TROY expression in microglia by siRNA transfection significantly inhibits microglial migration towards CNS-1 cells similar to 10 µM propentofylline treatment. These results identify TROY as a novel molecule expressed in microglia, involved in their migration and targeted by propentofylline. Furthermore, these results describe a signaling molecule that is differentially expressed between microglia and macrophages in the tumor microenvironment."

Protocol: Small interference RNA (siRNA) oligonucleotides specific for TROY (#1:s144862, #2:s144863, #3:s144864) were validated by and purchased from Invitrogen (Grand Island, NY). Transient transfection was carried out using iFect (Neuromics Edina, MN) as previously described [J Am Soc Nephrol 17: 1543–1552]. Briefly, microglia were plated at 3×105 cells/well in a 12-well plate. Once cells had adhered, they were transfected with 1 µg siRNA. Control samples were treated with empty vector siRNA (Sigma St Louis, MO) or iFect reagent alone. Cells were left in microglia media (10% fetal bovine serum (Hyclone Logan, UT), 1.1% GlutaMax (Invitrogen Carlsbad, CA), and 1% penicillin/streptomycin (100 U/ml penicillin, 100 µg/ml streptomycin, Mediatech, Manassas, VA)) at 37°C with 5% CO2 overnight and then used the following day for experiments.